Epidemiological Investigation Of Dog Obesity And Analysis Of Biomarkers

Being overweight and obese are increasingly common and serious health problems for pets.In different countries and regions,the incidence of canine obesity ranges from 20% to50%.The impact of obesity on health includes abnormal body shape and posture,decreased quality of life,increased risk of cardiovascular disease,orthopedic disease,respiratory dysfunction,endocrine dysfunction,and other diseases,which can lead to a shortened lifespan.Obviously,pet obesity has become a huge challenge for small animal clinics.Therefore,surveying on the incidence of canine obesity in Xi’an and screening for early diagnostic markers of canine obesity can provide important basic data and technical support for understanding the epidemiological patterns of canine obesity in Xi’an and for early screening and intervention of canine obesity.In this study,155 canine cases that visited Xi’an Animal Hospital of Northwest A&F University from October 2021 to October 2022 were surveyed on-site using a questionnaire.Body condition score(BCS)was used to determine whether the dogs were obese.Factors such as breed,diet,and living environment were investigated and their relationship with obesity was analyzed to form epidemiological data.Eighteen adult Golden Retrievers without underlying diseases were randomly selected from the visiting dogs and divided into three groups according to BCS: Lean group,Overweight group,and Obese group,with six dogs in each group.Blood samples were collected for plasma biochemical index detection and a liver ultrasound examination was performed to preliminarily determine the changes in plasma biochemical indexes and liver imaging in obese dogs.16 S rRNA sequencing technology is a commonly used method for analyzing the composition of digestive tract microbial communities.Anal swab samples were collected for 16 S rRNA sequencing analysis of intestinal microbial diversity.Based on the Illumina sequencing platform,transcriptome sequencing analysis was performed on whole blood samples from the three groups of dogs.The following results were obtained from the survey:1.Epidemiological survey of canine obesity in Xi’an: Through a survey of 155 dogs,it was found that the incidence of canine obesity was about 49.03%.Among them,the obesity rate of female dogs was significantly higher than male dogs(p<0.01);the obesity rate of middle-aged dogs was significantly higher than young and old dogs(p<0.01);the obesity rate of neutered dogs was significantly higher than non-neutered dogs(p<0.01);the obesity rate of dogs participating in multiple sports was significantly lower than dogs only going out for walks(p<0.05).The rate of dog obesity in households with multiple animals at the same time was significantly higher than in households with only one dog(p<0.05).2.Plasma biochemical and liver imaging analysis of obese dogs: Plasma biochemical index examination showed that the triglyceride concentration in the Obese group was1.30±0.39 mmol/L,significantly higher than that in the Lean group(p<0.01);the cholesterol concentrations in the Overyweight group and Obese group were 7.44±2.41 mmol/L and8.1±0.51 mmol/L respectively,both significantly higher than that in the Lean group(p<0.05);the low-density lipoprotein concentration in the Obese group was 6.74±0.59 mmol/L,significantly higher than that in the Lean group(p<0.01);the leptin concentration in obese dogs was 2.46±0.15 ng/m L,significantly higher than that in the Lean group(p<0.01);while the high-density lipoprotein concentration in the Obese group was 3.65±0.66 mmol/L,significantly lower than that in the Lean group(p<0.01).Liver ultrasound results showed that the intrahepatic ducts in overweight and obese dogs were not as clear as those in normal dogs.3.The impact of obesity on canine intestinal flora: The results of 16 S rRNA sequencing revealed that the abundance and diversity of intestinal microflora in Obese group were lower than those in Lean group but did not reach statistical significance.The relative abundance of Bacteroidetes and Firmicutes is positively correlated with the degree of obesity;the relative abundance of Actinobacteria,Bifidobacterium,and Lactobacillus is positively correlated with the degree of obesity,but the differences between groups are not significant(p>0.05).LEf Se analysis found that Holdemanella and Bacteroides fragilis are biomarkers for the Lean group.Anaerobiospirillum and Anaerobiospirillum succiniciproducens are biomarkers for the Overweight group.Syntrophia and Porphyromonas pasteri are biomarkers for the Obese group.4.Screening for differentially expressed genes in canine obesity: The results showed that a total of 954 DEGs were screened between Lean group and Overyweight group with406 up-regulated genes and 551 down-regulated genes;a total of 810 DEGs screened between Lean group and Obese group with 351 up-regulated genes and 459 down-regulated genes;DEGs were significantly enriched in pathways such as glycine serine and threonine metabolism,β-alanine metabolism,lysine degradation,pentose phosphate pathway,p53 signaling pathway,hematopoietic cell lineage,and complement coagulation cascade etc.In summary,the incidence of canine obesity in Xi’an is 49.03%.Gender,age,neutering,and exercise factors are significantly correlated with canine obesity.Plasma biochemical indexes such as triglycerides,total cholesterol,low-density lipoprotein,and leptin levels are positively correlated with obesity,while high-density lipoprotein levels are negatively correlated with obesity.The abundance and diversity of intestinal microflora in obese dogs are lower than those in lean dogs.Compared with lean dogs,the DEGs in overweight and obese dogs are enriched in pathways such as protein metabolism and sugar metabolism.The research results provide basic materials for pet dog obesity-related research.